Ok .. this may sound stupid but its worth a try!
Get your harddrive and put it in a freezer bag, or plastic bag.. doesn't matter. Leave it in there for 30-40 mins.
Then take it out, and run to the computer.. plug it in [leave it in the bag].. try to get all the water n shit off the bag first.
You should get the h-d on its last limbs.. then get your money back :@
And no i'm not joking this saved 30gb of essential data I needed before
Good-luck dude!
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Oh and if you know what your doing, unscrew the top and take a look for yourself.. however try the freezer first. cause once the top is off.. if you screw it up while putting it back on your only choice is professional recovery ^^